Step 11: Draw the bottom part of Leonardo's head by using the original circle as a guide. Follow the basic path of the circle as you darken the line but make the sides bulge out more to create the cheeks. The bottom part should be higher too. Draw a line under the mask for extra detail.
Step 12: On the left side of the head, draw the first end of Leonardo's mask, which consist of two wavy lines that come together at a point.
Step 13: Draw the other end of Leonardo's mask the same way, except one of the lines should be shorter because it's behind the first shape.
Step 14: That’s it! You now have a nice sketch of Leonardo from Teenage Mutant Ninja Turtles. You can stop at this quick drawing for a rough, sketchy look or go for a more finished look by continuing to the step below.
Step 15: For a more finished, inked look, carefully draw over the final sketch lines with a pen or marker. Wait for the ink to dry, and then get rid of every pencil mark with an eraser. You now have a finished inked drawing of Leonardo! You can stop here or go to the final step to complete your Leonardo drawing.
Final Step: For a completely finished Leonardo drawing, you have to color it. You can use markers, color pencils or even crayons! His skin is light green. You can use dark green on the side of his head to give the head more dimension and volume. Color his eyes light blue. Leonardo's signature color is blue, so color his mask blue. That’s it! You now have a completed drawing of Leonardo from Teenage Mutant Ninja Turtles.